TY - JOUR A1 - Bernal, S. A. A1 - Dhandapani, Y. A1 - Elakneswaran, Y. A1 - Gluth, Gregor A1 - Gruyaert, E. A1 - Juenger, M. C. G. A1 - Lothenbach, B. A1 - Olonade, K. A. A1 - Sakoparnig, M. A1 - Shi, Z. A1 - Thiel, C. A1 - Van den Heede, P. A1 - Vanoutrive, H. A1 - von Greve-Dierfeld, S. A1 - De Belie, N. A1 - Provis, J. L. T1 - Report of RILEM TC 281-CCC: A critical review of the standardised testing methods to determine carbonation resistance of concrete N2 - The chemical reaction between CO2 and a blended Portland cement concrete, referred to as carbonation, can lead to reduced performance, particularly when concrete is exposed to elevated levels of CO2 (i.e., accelerated carbonation conditions). When slight changes in concrete mix designs or testing conditions are adopted, conflicting carbonation results are often reported. The RILEM TC 281-CCC ‘Carbonation of Concrete with Supplementary Cementitious Materials’ has conducted a critical analysis of the standardised testing methodologies that are currently applied to determine carbonation resistance of concrete in different regions. There are at least 17 different standards or recommendations being actively used for this purpose, with significant differences in sample curing, pre-conditioning, carbonation exposure conditions, and methods used for determination of carbonation depth after exposure. These differences strongly influence the carbonation depths recorded and the carbonation coefficient values calculated. Considering the importance of accurately determining carbonation potential of concrete, not just for predicting their durability performance, but also for determining the amount of CO2 that concrete can re-absorb during or after its service life, it is imperative to recognise the applicability and limitations of the results obtained from different tests. This will enable researchers and practitioners to adopt the most appropriate testing methodologies to evaluate carbonation resistance, depending on the purpose of the conclusions derived from such testing (e. g. materials selection, service life prediction, CO2 capture potential). KW - Concrete KW - Cement KW - Carbonation KW - Testing KW - Standards PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609364 DO - https://doi.org/10.1617/s11527-024-02424-9 VL - 57 SP - 1 EP - 31 PB - Springer Nature AN - OPUS4-60936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - van den Berg, A. A1 - Adriaans, K. A1 - Hoppener, E. A1 - Parker, L. A1 - Boersma, A. A1 - Altmann, Korinna A1 - Legler, J. A1 - Pieters, R. T1 - Inflammation-related key events stimulated by micro- and nanoplastics N2 - The presence of micro- and nanoplastic particles (MNP) in our environment has raised increasing public and political concern. Increasing evidence suggests that humans are exposed to these MNP, mostly via inhalation or ingestion. The EC-Horizon project POLYRISK (https://polyrisk.science) aims to establish an IATA/AOP-based tiered approach to assess human health risks of MNP. In our research, we focus on assessing immunotoxicological effects of MNP. We have tested a series of primary, secondary, environmentally aged (incubated in River Rine water) and chemically altered MNP for their potential to affect dendritic cells or macrophages. MNP used in this study include primary and weathered PS, secondary PVC, PA, PP (with or without talc) and PE. The secondary PE and PP (w/o talc) particles appeared to have oxidized groups on their surface. Data shows that MNP can be engulfed by macrophages (PMA-stimulated human THP1 cells) and human blood-derived dendritic cells (DCs). The effects of virgin as well as secondary MNP (0, 10 or 100 μg/ml) on THP1 macrophages were limited to decrease of mitochondrial activity (Alamar blue), increase of cellular leakage (LDH), and stimulation of lysosomal activity. None of these MNP stimulated gene expression of NFκB or release of pro-inflammatory cytokines (IL-6, TNFα, IL-1β). On the other hand, secondary PP and PE with oxidized surface groups did increase NFκB gene expression and release of cytokines by THP1 macrophages. Virgin and weathered PS particles were tested using DCs, and only weathered PS did stimulate DC activity (increased costimulatory molecules CD83, CD86) and as consequence allogeneic T cells. DC activation appeared to result from environmental contaminants. In conclusion, of all MNPs tested only those that contained active surface groups or environmental components appeared to be immunostimulatory, whereas primary and secondary MNP rather reduced macrophage activity and viability (at relatively high concentrations of 100 μg/ml). Further research is needed to reveal molecular mechanisms and to translate in vitro findings to real-world exposure scenarios. T2 - 58th Congress of the European Societies of Toxicology (EUROTOX 2024) CY - Copenhagen, Denmark DA - 08.09.2024 KW - Micro- and nanoplastic particles (MNP) KW - Human health risks KW - Immunotoxicological effects PY - 2024 DO - https://doi.org/10.1016/j.toxlet.2024.07.052 AN - OPUS4-63363 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -